Working out during your second and third trimester is just as beneficial now to your labor and delivery as working out during your first trimester. A few things need to be tweaked now because of your growing belly and the weight that's placed in your middle; the loosening of your ligaments also presents a challenge that requires modification.

Lets meet our lovely mama, Jen! Jen is pregnant with her second daughter and is pictured here at 32 weeks.

First things first when doing any exercise during the second and third trimester you'll want to use light weights, no heavier than eight pounds, making sure that you're supported by either sitting or leaning against a wall. Anytime you begin to feel lightheaded or dizzy stop exercising and have some water.

By using light weights you can still tone your biceps, triceps and shoulder muscles by sitting in a chair. Be mindful of your form making sure to get the most out of your workout. Try to do high reps if you can with the lighter weights, either do 10 reps or 12 reps three times.

Instead of doing crunches to keep your core muscles strong do pelvic tilts. You can do these standing up by pushing your pelvis forward and the backward. You can also do it on all fours like Jen here.

Squats are a really excellent fat burning exercise because its a major muscle group. Those bigger muscle groups require more energy to be used so you'll burn fat longer by working them. Modify the squats later in pregnancy by using a chair to steady yourself or using a wall.

Last but certainly not least don't forget to keep up that cardio! If you're newly into your second trimester continue to jog, keeping in mind that any time you feel light headed or dizzy you should walk at a brisk pace and drink some water. Once you're farther along, like Jen is, walk at either a moderate or brisk pace for about 20 to 30 minutes. Its important that you keep yourself hydrated! Water, water, water!!

Hopefully you'll see the benefits both short term and long term to remaining active during your pregnancy. I have no experience with prenatal yoga but everything Ive read has only had nothing but rave reviews as well as recommendations for it. Its a low impact workout and is very gentle on your joints and ligaments. So check it out OR if you've done prenatal yoga tell me your thoughts! Who knows, perhaps one of these days Ill try my hand at a third pregnancy! (Not now though, I have a half marathon to run in May!)

So do you find these tips helpful? Have you been wondering how you can maintain an active and fit lifestyle while pregnant? We'd love to hear from you.

Bio: Bert is a stay at home mom of two, wife to college sweetheart, and what she calls a "semi-crunchy" mama. After four years of being overweight related to pregnancies, Bert submitted a video entry into a local Biggest Loser type of fitness challenge; she was chosen and lost 25% of her body weight in 90 days. She blogs at FirstTimeMom about everything from cloth diapers, parenting, life and her recent passion with health and fitness.